I also have this issue. It lets you turn the switch on, but when you enter the world, exit the world configuration menu, or switch tabs in the world configuation menu (eg. switch to resource packs or multiplayer), it turns the switch back off. Also (this could be entirely unrelated to the issue or unintentional) there only seems to be one 'experiments' switch on ios? I have seen multiple options for this on youtube videos and reddit. I only seem to have the one. I hope this helps! (I'm playing on iphone 7 if that information is needed).
Sam Marfleet
I also have this issue. It lets you turn the switch on, but when you enter the world, exit the world configuration menu, or switch tabs in the world configuation menu (eg. switch to resource packs or multiplayer), it turns the switch back off. Also (this could be entirely unrelated to the issue or unintentional) there only seems to be one 'experiments' switch on ios? I have seen multiple options for this on youtube videos and reddit. I only seem to have the one. I hope this helps! (I'm playing on iphone 7 if that information is needed).